摘要
优先流是一种快速非平衡的土壤水分运动,优先流现象极大地影响了坡面地表径流及地下径流的形成和运动过程,作为土壤水分一种特殊运动形式,优先流是当今世界水文学研究的重点和难点问题之一。
本文主要以长江三峡库区林地坡面优先流为研究对象,以湖北省秭归县曲溪小流域为试验基地,选择曲溪小流域内典型林地坡面,采用剖面灌水法分析了优先路径在土壤剖面上的水平分布和垂直分布特性、优先流运动特征、影响优先流的因子、优先流对剖面渗流和地表径流的影响。在此基础上,修正了优先流模型。得出主要结论如下:
(1)优先流是长江三峡花岗岩区林地坡面的一种普遍现象,观测的优先流雷诺数均大于10,说明优先流运动不遵从达西定律。在该地区存在两种类型的优先路径,即地质型优先路径(原生型优先路径)和生物型优先路径(次生型优先路径)。优先路径主要分布在距地表以下0.8~1.0m范围内,在土层中的分布呈聚集状分布,其拥挤度为6.0~19.0,优先路径的平均密度为5~7个/m。
(2)优先流产流过程表现为明显的涨水、峰值和退水3个阶段。涨水历时较短,退水历时较长。长江三峡花岗岩地区优先流产流滞后降雨时间为5~95.5h,优先流历时为7~170h。优先流产生后,峰值流量出现时间为产流后1~13h,大部分场降雨产生的优先流在产流后1~2h就达到峰值流量。当前期降雨(3~7日降雨量)充分后,只要再有较小的降雨,都可能产生优先流。
(3)降雨和土壤物理特性是影响优先流的重要因子,影响优先流流量的主要降雨因子是降雨总量,两者呈现出极显著的正相关关系;影响优先流历时的主要降雨因子是降雨历时和降雨总量,优先流历时与降雨历时为极显著正相关关系,与降雨总量为显著正相关关系;影响优先流峰值流量的主要降雨因子是降雨总量,两者为显著正相关关系。优先流滞后降雨的时间与降雨各因子线性关系均不显著。>20mm/h降雨量和最大降雨强度与优先流各因子均不存在显著性相关关系。试验地不同土层之间土壤物理性质差异较大,不同土层土壤物理性质的显著差异导致土壤水分运动中产生侧向优先流。
(4)优先流流量占剖面渗流总量的比例可达2.40%~48.72%,其水分通量最大可达剖面渗流水分通量的17200倍。这说明优先流对降雨的快速入渗有较大作用,能够加速渗流流动速度,会在很大程度上增加土壤水分运动通量。该结果与国外研究结果较为一致。
(5)同等降雨及下垫面条件下,受降雨量影响,对应的优先流总量和坡面径流总量呈一元线性正相关关系,回归方程为:
Abstract: Preferential flow is a kind of non-equilibrium movement of soil water. It influenced greatly on the formation and movement of surface runoff and underground (subsurface) runoff. As a kind of special movement form of soil water, preferential flow is one of the most important and difficult problems in current research about hydrology.In this paper, the Quxi watershed of Zigui county, Hubei province, was selected as the experimental site. In a slope of forestland, the distribution characteristics of preferential flow were analyzed by the method of irrigating. The moving characteristics of preferential flow, the factors influencing preferential flow, and the effect of preferential flow on infiltrated flow and surface runoff were also analyzed. Based on that, the preferential flow model was modified. The main conclusions were as the following:(1) Preferential flow is very common in the granite area of the Three-Gorges, Yangtze River. Its Re is bigger than 10, which shows that the movement of preferential flow does not follow Darcy-Law. There exist two kinds of preferential paths in this area, namely original preferential paths and secondary preferential paths. Preferential paths mainly exist in the soil layer of 0.8~1.0m under ground, which is gatherly distributed with index of 6.0-19.0. The mean number of existed preferential paths is 5~7/m.(2) The process of preferential flow is obviously divided into 3 phases: increasing phase, peak, and decreasing phase. Its increasing phase is very short, while decreasing phase is very long. Normally, preferential flow appeared 5-95.5h later than precipitation. Its duration time is 7-170h. Most preferential flow reach their peak l~2h after their appearance. In the condition of abundant antecedent rainfall, preferential flow will appear even with little precipitation.(3) Precipitation and soil characteristics are the most important factors influencing preferential flow. The main factor influencing the amount of preferential flow is the amount of rainfall, which is evidently positively related to the amount of preferential flow. The main factors influencing the duration of preferential flow are the duration and the amount of rainfall. The duration of preferential flow is very evidently positively related to the duration of rainfall, and evidently positively related to the amount of
rainfall. The main factor influencing the peak of preferential flow is the amount of rainfall, which is evidently positively related to the peak of preferential flow. The soil characteristics of different soil layers are very different, which induced the lateral preferential flow.(4) The ratio of preferential flow to infiltrated flow may reach 2.4%~48.72%. Its shuifentongliang may be 17200 times of that of infiltrated flow, which shows that preferential flow has great effect on the quick infiltration of precipitation. Preferential flow could increase the moving velocity of infiltrated flow and increase the shuifentongliang of soil water in a great extent.(5) Comparing the amount of preferential flow and amount of surface runoff, it is found that they have the positively linear related relationship. The equation is as the following:y = 0.7761x + 0.0379 (R2=0.8294, R=0.9107)In one rainfall, the more the amount of preferential flow is, the more the amount of surface runoff is. So do the inverse situation. In one rainfall, the increase of the amount of preferential flow induced the decrease of the amount of surface runoff. The appearance of preferential flow delayed the appearing time of the peak of surface runoff, increased the increasing duration of surface runoff, and prolonged the total duration of surface runoff.(6) Based on the data measured in lab and in the field, the preferential flow model is set up as the following equation:The simulated value matched better with measured value in surface soil than it does in deep layers. The simulated results showed that the effective path-length is 150mm in the soil layer 83-110cm, the longest of all the soil layers, which meant that pre
引文
1 程金花,张洪江,史玉虎.三峡库区花岗岩林地土壤特性与“优先路径”关系.中国水土保持科学,2005,3(1):97-101
2 程云,张洪江,史玉虎等.长江三峡花岗岩坡面土管分布研究.北京林业大学学报,2001,23(5):19-22
3 程云.长江三峡花岗岩坡面土管分布及管流特性研究.北京林业大学研究生院,硕士学位论文,2002.6
4 程竹华,张佳宝.土壤中优势流现象研究进展.土壤,1998(6):315-318
5 冯杰,郝振纯.水及溶质在有大孔隙的土壤中运移机制研究进展.河海大学学报,2002,30(2):63-70
6 郝振纯,冯杰.水及溶质在大孔隙土壤中运移的实验研究进展.灌溉排水,2002,21(1):67-71
7 何凡,张洪江,程金花等.长江三峡花岗岩坡面管流与渗流试验研究.水土保持通报,2004,24(6):10-15
8 黄冠华,叶自桐等.一维非饱和溶质随机运移模型的谱分析.水利学报,1995,11:1-7
9 黄冠华,沈荣开.非均质土壤中二维非饱和土壤水分运动的随机分析.水科学进展,1997,8(2):117-122
10 康绍忠.土壤水分动态的随机模拟研究.土壤学报,1990,27(1):17-24
11 雷志栋,杨诗秀,等.土壤水动力学.北京:清华大学出版社,1988.276P
12 雷志栋,胡和平,杨诗秀.土壤水研究进展与评述.水科学进展,1999,10(3):312-318
13 刘亚平,陈川.土壤非饱和带中的优先流.水科学进展,1996(3):85~89
14 卢玉邦.土壤水分预测模型研究.土壤学报,1989,26(1):51~56
15 倪余文,区自清.土壤优先水流及污染物优先迁移的研究进展.土壤与环境,2000,9(1):60-63
16 牛健植.长江上游暗针叶林生态系统优先流机理研究.北京林业大学研究生院,博士学位论文,2003.9
17 秦耀东,任理,王济.土壤中大孔隙流研究进展与现状.水科学进展,2000,11(2):203-207
18 秦耀东,胡克林.大孔隙对农田耕作层饱和导水率的影响.水科学进展,1998,9(2):107-111
19 任理.有限解析法在求解非饱和土壤水流问题中的应用.水利学报,1990, 10:55-61
20 王超.氮类污染在土壤中迁移转化规律试验研究.水科学进展,1997,8(2):176-182
21 杨大三,袁克侃 编著.鄂西三峡库区防护林研究.湖北科学技术出版社,武汉,1996.12
22 杨金忠,叶自桐 等.野外非饱和土壤中溶质运移试验研究.水科学进展,1993,4(4):245-252
23 杨金忠,叶自桐.野外非饱和土壤水流运动速度的空间变异性及其对溶质运移的影响.水科学进展,1994,5(1):9-17
24 张洪江,王玉杰,北原曜等.长江三峡花岗岩坡面管流实验研究.北京林业大学学报,2000,22(5):53-57
25 张洪江,程云,史玉虎等.长江三峡花岗岩坡面林地土管特性及其对管流的影响.长江流域资源与环境,2003,12(1):55-60
26 张洪江,程云,史玉虎等.长江三峡花岗岩坡面管流产流特性研究.水土保持学报,2001,15(1):5-8
27 张洪江,程金花,史玉虎等.三峡库区花岗岩林地坡面优先流对降雨的响应.北京林业大学学报,2004,26(5):6-9
28 张洪江,王礼先,长江三峡花岗岩坡面土壤流失特性及其系统动力学仿真,北京:中国林业出版社,1997:p12-22
29 张瑜芳,张蔚榛,等.排水农田中氮素转化运移和流失.武汉:中国地质大学出版社,1997.P184
30 朱学愚,谢春红等.非饱和流动问题的SUPG有限元素数值法.水利学报,1994,6:37~42
31 小谷野多美枝,新藤静夫,地下侵食特性,役割,1992,地形,13(3),p.239
32 井上久义,圃场土壤中大孔隙水·溶质移动果役割,农土论集 132,p.111-120,1987
33 北原曜,Sidle R.C.,寺岛智己,中井裕一郎,人工用饱和侧方流实验,103回日林论,p.589-591,1992b
34 北原曜,中井裕一郎,一次谷流域河川流量流量关系,日林志,74(1),p49-54,1992c
35 北原曜,森林土壤流特性,水文·水资源学会志,5(1),p.15-25,1992a
36 北原曜.流大孔隙关研究史[J].水利科学,1996,39(6):80~114
37 Ajuha. L. R. RZWQM. Components dealing with water and chemical transport in soil matrix and macrbpores. Internal Report US Dept of Agriculture-Agricultural Research Service. National Agr Water Quality Lab, Durant, OK, 1991
38 Anderson S. H., Peyton R. L., Gantzer C. J., Evaluation of constructed and natural soil macropores using x-ray computed tomography, Geoderma, 46, 1990 p. 13-29
39 Anderson J. L., Bouma J. Water movement through pdal soils: I Saturated flow. Soil Sci. Soc. Am. J., 1994a, 41: 413-418
40 Andreini. M. S., T. S. Steenhuis. Preferential paths of flow under conventional and conservation tillage. Geoderma. 1990, 46: 85-102
41 Andreu, L., F. Moreno, N.J. Jarvis et al. Application of the model Macro to water movement and salt leaching in drained and irrigated marsh soils Marismas, Spain. Agriculture Water Management. 1994, 25: 71-88
42 Baker, R.S., D. Hillel. Laboratory tests of a theory of fingering during infiltration into layered soils. Soil Science of America 1990, 54: 20-30
43 Bejat. L., F. Perfect., V. I., Quisenberry. Et al. Solute transport as related to soil structure in unsaturated intact soil blocks. Soil Science of America. 2000, 64: 818-826
44 Beven.K.J. Modeling preferential flow: A nuncerta infuture, in Preferential Flow. Edited by TJGish, AShirmohammadi. American Society of Agricultural Engineers, StJoseph, Mich, 1991.1-11
45 Bodvarsson G.S., Wu Y. S., Zhang Keni. Development of discrete flow paths in unsaturated fractures at Yucca Mountain. Journal of Contaminant Hydrology. 2003, (63): 23-42
46 Booltink H. W. G., Field-scale distributed modeling of bypass flow in a heavily textured clay soil, J. Hydrology 163, p.65-84, 199439. Aubertin G M., Nature and extend of macropores in forest soils and their influence on subsurface water movement. U. S. D. A. Forest Service Research Paper, NE-192, 1971
47 Booltink H. W. G., HatanoR, et.al. Measurement and simulation of bypass flow in a structured clay soil: A physical morphological approach. Journal of Hydrology, 1993, 148: 149-168
48 Bouldin J. D., Freeland R. S., Yoder R. E. et al. Nonintrusive mapping of preferential water flow paths in West Tennessee using ground penetrating radar. Proceedings of the Seventh TN Water Resources Symposium, 1997. Feb. 24-29. Nashville, TN
49 Bouma, J. Field measurement of soil hydaulic properties characterizing water movement through swelling clay soils. Journal of Hydrology. 1980,45: 149-158
50 Brakensiek, D.L., Rawls, W.J., Logsdon, S.E., et al. Fractal description of macroporosity. Soil Science Society of America Journal of Soil Science 1992, 56: 1721-1723
51 Bruggeman.A.C, SMostaghimi. Simulation of preferential flow and solute transport using an efficient finite element model. In Preferential Flow,edited by TJGish,AShirmohammadi.American Society of Agricultural Engineers. StJoseph, Mich, 1991,3:244-255
52 Cameira, M. R. L. Ahuja, R. M. Femanolo, L. S. Pereira, Evaluating field measured soil hydrautic properties in water transport simulations using the RZWQM, Journal of Hydrology, 2000, (236): 78-90
53 Chen.C, Thomas.D.M, Green.R.E,et.al..Two-domaine stimation of hydraulic in macropore soils. Soil Sci Soc AmJ, 1993, (57): 680-686
54 Chen.C, Wagenet. R.J. Simulation of water and chemicals in macropore soils,2. application of linear filter theory. Journal of Hydrol, 1992b, 130: 127-149
55 Chen.C, Wagenet.RJ. Simulation of water and chemicals in macropore soils, 1 .representation of the equivalent macropore influence and its effect on soil-water flow[J].JHydrol,1992a,130:105~126
56 Cindy M. Cooke, George Shaw, Chris D. Collins. Determination of solid - liquid partition coe.cients (Kd)for the herbicides isoproturon and tri.uralin in.ve UK agricultural soils. Environmental Pollution 2004 (132): 541-552
57 Corwin.D.L, Waggoner.B.L, Rhoades.J.D. A functional mode of solute transport that accounts for by pass. Journal of Environment Quality, 1991, 20: 647
58 Crestana R., Timothy R. Albert J. et al. An improved dual porosity model for chemical transport in macroporous soils. Journal of Hydrology, 1993, 193: 270-292
59 Cristian Marchioli, Andrea Giusti, Maria Vittoria Salvetti, et al. Direct numerical simulation of particle wall transfer and deposition in upward turbulent pipe. International Journal of Multiphase Flow. 2003, (29): 1017-1038
60 Daniel Hillel. Environmental soil physics. Academic Press, 1998: 188-190
61 Edwards.W.M, Norton.L.D, Redmond.C.E. Characterizing macropores that affect in filtration into nontilled soil. Soil Science Society of America Journal, 1988, 52(2): 483-487
62 Ehlers.W, Kopke.U, Hesse.F, et.al.. Penetration resistance and root growth of oatsin tilled andun tilled loose soil. Soil Tillages, 1983,2 (3): 261-275
63 Freeland R.S. Yoder, R. E. Ammons, D. T., Observating preferential flow paths beneath West Tennessee;s loess terrains using ground penetrating radar. Tennessee Agri Science, 1997, Winter, No. 181
64 Flury.M, Fluhler.H. Susceptibity of soils to preferential flow of water: A field study. Water Resoures, 1994,30:1945-1954
65 Gautom, M. R. Watanabe, K. Saegiss, H. Runoff analysis in humid forest catchment with artificial neural network, Journal of Hydrology, 2000 (235): 117-136
66 Gerke.H.H, van Genuchten. M.T. A dual-porosity model for simulating the preferential movement of water and solutes in structured porous media. Water Resoures Research ,1993a, 19(2): 305-319
67 Gerke.H.H, van Genuchten. M.T. Evaluation of a first-order water transfer term for variably saturated dual-porosity flow models. Water Resoures Research, 1993b, 29(4): 1225-1238
68 Gerke.H.H, van Genuchten.M.T. Adual porosity model for simulating the preferential movement of water and solute sinstructured porousmedia. Water Resoures, 1993,29:305-319
69 Germann P. Preferential flow and the generation of runoff, 1 .Boundary layer flow theory. Water Resoures, 1990, 26: 3055-3063
70 Germann.P. F, Beven.K. Kine mafic wave approximation to infiltration to soils with sorbing macropores. Water Resoures, 1985, 21:990-996
71 Germann.P. Preferential flow and generation of runoff, 1,boundary layer flow theory. Water Resoures Research, 1990, 26: 3055-3063
72 Germann.P.F, BevenK. Water flow in soil macropores, I . An experimental approach. Soil Scince, 1981, 32:1-13
73 Gjettermann B., Nielsen K.L., Petersen C.T. et al. Preferential flow in sandy loam soils as affected by irrigation intensity Soil Technology, 1997,11: 139-152
74 Helling. C.S, Gish. TJ. Physical and chemical processes affecting preferential flow[A]. In Preferential flow Proc National Symposium[C]. TJGish, Shirmohammadi, eds. American Society of Agricultural Engineers, StJoseph, MI, 1991,77
75 Hill. D. Environmental soil physics. Academic press, 1998,188-190
76 Hillel.D. Application of Soil Physics. Academic Press, NewYork,1980.312P
77 Horst H. Gerke, J. Maximilian Kohne. Dual-permeability modeling of preferential bromide leaching from a tile-drained glacial till agricultural field. Journal of Hydrology 2004 (289): 239-257
78 Jarvis.NJ, Bergstrom. L., PEDik. Modelling water and solute transport in macroporous soils, chloride break through under non-steady flow. JSoilSci, 1991b, 42: 71-81
79 Jarvis.NJ, Janssson..P.E., PEDik, et.al.. Modelling water and solute transport in macroporous soils, I, modeldes cription and sensitivity analysis. J Soil Sci, 1991a, 42:59-70
80 Jurg Hosang. Modelling preferential flow of water in soils-a two phase approach for field conditions. Geoderma, 1993, 58:149-163
81 Kamra S.K., Lennartz B., Van Genuchten M.Th., et al. Evaluating non-equilibrium solute transport in small soil columns. Journal of Contaminant Hydrology 2001,48: 189-212
82 Karvonen, T. Koivusalo H., Jauhiainen, M. Palko, J. Weppling, K. Ahydrological model for predicting runoff fome different land use, Journal of Hydrology, 1999 (217): 253-265
83 Kitahara Hikaru.The study history between pipeflow and macropores. Japan, hydraulic science, 1996,227:81-114
84 Kitahara,Hikaru.The property of pipe flow in forest stand. Journal of Japan Soc. Hydrol.&WaterRes.,1992,5(l):15-25
85 Kramer, J.H. and Cullen, S.J. 1995. Review of vadose zone flow and transport models. In: Vadose zone characterization and monitoring (Wilson L.G., Everett L.G., Cullen S.J., Eds.), CRC Press, Inc., 267-289
86 Landon, M., Delin, K.G. N., Komor, S. C. Regan, C. P. Comparison of the stable-isotopic composition of soil water collected from suction lysimeters, wick samplers, and cores in a sandy unsaturated zone, Journal of Hydrology, 1999 (224): 45-54
87 Larsson, M. H. Jarvis, N. J. Evaluation of a dual-porosity model to predict field-scale solute transport in a macroporous soil, Journal of Hydrology, 1999 (215): 153-171
88 Leaney.F.W, Smettsm.K.R.J, Chittleborough.D.J. Estimating the contribution of preferrntial flow to subsurfacw runoff from a hill slope using deuterium and dchloride. J Hydrol, 1993,147:83-103
89 Lukey, B. T. Sheffield, J. Bbathurst, J. C. Hiley, R.A. Mathys, N. Test of the SHETRAN technology for modelling the impact of reforestation on badlands runoff and sediment yield at Draix, France, Journal of Hydrology, 2000 (235): 44-62
90 Montas .H.J, Eigel.J.D, Engel.B.A,et.al.. Deterministic modeling of solute transportion soils with preferential flow pathways, Part 1. model development. American Society of Agricultureal Engineers, 1997,40(5): 1245-1256
91 Nieber J. L., Warner G. S., Soil pipe contribution to steady subsurface storm flow, Hydrological Processes 5, p.329-344, 1991
92 NieberJL,WarnerG S. Soil pipe contribution to steady subsurface storm flow. Hydrological Processes, 1991,5:329-344
93 Novak, S. M. Portal, J. M. Schiavon, M. Effects of soil type upon metolachlor losses in subsurface drainge, Chemosphere. 2001 (42): 235-244
94 Omoti.U, Wild.A. Use off luorescentdyes to mark the path ways of solute movement through soils under leaching condition, 2, fieldex-periment. Soil Science, 128: 98-104
95 Radulovich R., Solorzano E., Sollins P., Soil macropore size distribution from water breakthrough curves, Soil Sci. Soc. Amer. J. 53, p.556-559, 1989
96 Rob F. A. Handriks, Klaas Oostindie, Pirn Hamminga, Simulation of bromide tracer and nitrogen transport in a cracked slay soil with the FLOCR/ANIMO model combination, Journal of Hydrology, 1999 (215): 94-115
97 Robert Ludwiga, Horst H. Gerkeb, Ole Wendrothb. Describing water flow in macroporous field soils using the modifiedmacro model. Journal of Hydrology 1999,215: 135-152
98 Shalit.G, Steenhuis.T.S. A simple mixing layer model predicting solute flow to drainage lines under preferential flow. J Hydrol, 1996,183:139-149
99 Shipitaloa M.J., Dickb W.A., Edwardsa W.M. Conservation tillage and macropore factors that affectwater movement and the fate of chemicals. Soil & Tillage Research. 2000, 53: 167-183
100 SidleRC, KitaharaHikaru, TerajimaT, NakaiY. Experimental studies on the effects of pipe flow on through flow partitioning. Journal of Hydrology, 1995, 165: 207-219
101 Silberstein, R. P. Sivapalan, M. Wyllie. A. On the validation of a coupled water and energy balance model at small catchment scales. Journal of Hydrology, 1999 (220): 149-168
102 Stagnitti.F, Steenhuis.T.S., Parlange.J.Y., et.al.. Preferential solute and moisture transport in hill slopes [C]. In Challenges for Sustainable Development Proc. International Hydrology and Water Resources Symposium. Institution of Engineers, Barton, Australia, 1991, 919
103 Steenhuis.T.S, Boll.J, Shalit.G, et.al.. Simple equations for predicting preferential flow solute concentration. J Environ Qual, 1994,23:1058-1064
104 Steenhuis.T.S, Nijssen.B.M., F.Stagnitti, et.al.. Preferential solute movement in structured soils: Theory and application, in challenges for sustainable development proc[C]. International Hydrology and Water Resources Symposium, Institution of Engineers, Barton, Australia, 1991a, 925
105 Steenhuis.T.S, Parlange.J.Y, Andreini.M.S. An umerical model for preferential solute movement instructured soils. Geoderma, 1990,46: 193-208
106 Steenhuis.T.S, Parlange.J.Y. Preferential flow in structured and sandy soils, in Preferential Flow[M]. Edited by T.J.Gish, A Shirmohammadi, American Society of Agricultural Engineers. StJosephMich, 1991b. 12-21
107 Steenhuis.T.S, Parlange.J.Y, Andrenini.M.S. A numerical model for preferential solute movement in stractured soils. Geoderma, 1990,46: 193-208
108 Sten Bergstrom, Phil Graham L., On the scale problem in hydrological modelling, Journal of Hydrology 1999 (211) 253-265
109 Suzanne A. L. Role of macropore continuity and tortuosity on preferential transport of water and solute through soils. Phd thesis of Minnesota university, the United States
110 Tsuyohi, Miyazaki. Preferential Flow. Water Flow in Soils, 1992, 134-143
111 Van H. den Bosch, Ritsema, C. J. Boesten, J. T. I. Dekker, L. W. Hamminga, W. Simulation of water flow and bromide transport in a water repellent sandy soil using a one-dimensional convection-dispersion model, Journal of Hydrology, 1999(215): 172-187
112 VanGenuchten, FJ Leig, LJlund. Indirect Methods for Estimating the Hydraulic Properties of Unsaturated Soil. Proceedings of the International Work shop on Indirection Method for Estimating the Hydraulic Properties of Unsaturated Soil [M].California, USA, 1992. 468P
113 Van Ommen, H. C, van Genuchten, M. Th., van der Molen, W. H. et al. Experimental and theoretical analysis of solute transport rom a diffuse source of pollution. Journal of Hydrology. 1989, 105: 225-251
114 Vermeul.V.R, Istok.J.D, Flint.A.L, et.al. An improved method for quantifying soil macroposity. Soil Science Society of America Journal, 1993, 57:809-816
115 Virginia A. Brown, Jeffrey J. McDonnell, Douglas A.Burns, et al. The role of event water, a repid shallow flow component, and catchment size in summer storm flow. Journal of Hydrology 1999,217: 171-190
116 Wallach, R. and Steenhuis, T.S. 1998. Model for nonreactive solute transport in structured soils with continuous preferential flow paths. Soil Sci. Soc. Am. J. 62: 881-886
117 Wang.J.S.Y, T.N.Narasimhan. Hydrologic mechanisms governing fluid flow in apartially saturated, fractured, porous medium, Water Resources Reseach, 1991, 21: 1861-1874
118 Wang.J.S.Y. Flow and transport in fractured rocks[J].USNatl Rep Int Union Geod.Geophys. 1987-1990, Rev Geophys, 29 suppl, 1991,254-262
119 Warmer, G S., Xieber, I. D. R. A. Geise et al. Characterizing macrospores in soil by computed tomography, Soil Science Society of America. 1989: 53: 653-660
120 Waston, K. W. R. J. Luxmoore. Estimating macroporosity in a forest watershed by use of a tension infiltrometer. Soil Science Society of America. 1988: 50: 578-582
121 Webster, R. Quantitative spatial analysis of soil in the field. Advanced Soil Science 1985: 5: 1-20
122 Wendroth, O. Pohl, Koszinski, W. S. Rogasik, et al. Spatio-temporal and covariance structures of soil water status in two Northeast-German field sites, Journal of Hydrology, 1999, 215: 38-58
123 Workman.S.R, Skaggs.R.W. PREFLO: A water management model capable of simulating preferential flow. Trans, ASAE, 1990, 33: 1939-1948